2.9L Deisel won't rev over 2800 RPM
 

I have been fighting this problem for 8 months. 1st I'll describe what happened and then what I have tried to fix it.
MY CAR:
2003 Hyundai Terracan 2.9L VIN KMHNM81XP3U092447

SYMPTOMS:
I was driving up a fairly steep incline and accelerated through the last hairpin curve and everything was normal, no smoke
When I got to level ground 200 meters later my car would not rev over 2700 RPM, smoke.
Power band was 2200 - 2500 RPM but no turbo kick in.

ATTEMPTED FIXES:
Cleaned injectors and changed fuel filter
Replaced timing belt
Replace water pump
Replaced mass airflow sensor
Replaced high pressure fuel pump
Replaced turbocharger
Checked Acceleration Sensor & Actuator [3510042151]

CURRENT CONDITION:
Motor runs very smoothly and quietly
Revs to 2800 RPM
Power band 2100 - 2300 RPM
Turbo does not kick in.
Wallet is $2000 lighter

Any ideas as to what is causing this?